Anucleate bacterial cells (minicells) will be used to develop a model aging system. Anucleate cells cannot replenish their enzymes which must therefore age. Bacteriophage infection of anucleate cells causes immediate RNA and protein syntheses by transcription of the virus genome and translation of the mRNAs produced. It is proposed to analyze specific enzymatic activities and the ability of minicells to maintain their cellular metabolism over a period of aging. Strains carrying a combination of the mutation responsible for minicell production and other mutations known to be involved in control of protein degradation will be constructed. Aging of minicells from the constructed strains will be analyzed to detect genetic determinants of cellular fatigue. Virus infection of minicells of increasing age will be used to detect changes in the synthetic abilities of increasingly old minicells. It is proposed to analyze the viral products both by polyacrylamide gel electrophoresis and by direct enzymatic assay. The fidelity of T7 RNA polymerase synthesize in T7 infected minicells will be used to assay the correctness of protein synthesis in infected minicells of increasing age. The goal will be to detect cellular components which demonstrate the effect of aging either by loss of activity or change of activity.